mygpo/suggestions/tasks.py

   1 from itertools import chain
   2 from operator import itemgetter
   3 from collections import Counter
   4
   5 from mygpo.celery import celery
   6 from mygpo.db.couchdb.user import (suggestions_for_user,
   7     update_suggestions as update)
   8 from mygpo.subscriptions import get_subscribed_podcasts
   9
  10 from celery.utils.log import get_task_logger
  11 logger = get_task_logger(__name__)
  12
  13
  14 @celery.task(max_retries=5, default_retry_delay=60)
  15 def update_suggestions(user, max_suggestions=15):
  16     """ updates the suggestions of a user """
  17
  18     # get suggestions object
  19     suggestion = suggestions_for_user(user)
  20
  21     # calculate possible suggestions
  22     subscribed_podcasts = get_subscribed_podcasts()
  23     related = chain.from_iterable([p.related_podcasts for p in subscribed_podcasts])
  24
  25     # filter out blacklisted podcasts
  26     related = filter(lambda pid: not pid in suggestion.blacklist, related)
  27
  28     # get most relevant
  29     counter = Counter(related)
  30     get_podcast_id = itemgetter(0)
  31     suggested = map(get_podcast_id, counter.most_common(max_suggestions))
  32     update(suggestion, suggested)